Compressor lubrication system



July 25, 1961 CHEW 2,993,641

COMPRESSOR LUBRICATION SYSTEM Filed July 25, 1958 3 Sheets-Sheet l INVENTOR: R OY T. C H EW July 25, 1961 R. T. CHEW COMPRESSOR LUBRICATION SYSTEM 5 Sheets-Sheet 3 Filed July 25, 1958 M K .Y m w n m E V H m C 1+ T. VI m R I Y B \n w a .[II wl l hl n 1H WI IHH i z m w a 6 m F Patented July 25, 1961 2,993,641 COMPRESSOR LUBRICATION SYSTEM Roy T. Chew, 11322 S. Michigan, Ave., Chicago 28, Ill. Filed July 25, 1958, Ser. No. 750,930 1 Claim. (Cl. 230-206) This invention relates to oil-pressured lubrication systems for high speed reciprocating compressors of gaseous fluid.

The main objects of this invention are to provide an improved pump-pressured lubricating system for the various rotating and reciprocating parts of certain types of machine; to provide an improved lubricating system of this kind particularly adapted for use with high speed compressors; to provide a compressor lubricating system having an improved built-in arrangement of pressured oil distribution incorporated in the compressor housing structure and wherein the oil pump unit is a removable, externally accessible, component powered directly from the main compressor shaft; to provide such a compressor lubricating system wherein the oil pump unit may be removed and replaced without in any way disturbing the compressor assembly or installation; and to provide an improved pump-pressured lubricating system of this kind which is simple in construction, economical to manufacture, efficient in operation, and more easily maintained.

A specific embodiment of this invention is shown in the accompanying drawings in which:

FIGURE 1 is a schematic, partly phantom perspective view, partly broken away, of a particular type of compressor equipped with pump-pressured lubricating system constructed in accordance with this invention;

FIG. 2 is a top plan view of the same, a portion being broken away to more clearly illustrate interior arrangement thereof;

FIG. 3 is a vertical sectional view of the construction shown in FIGS. 1 and 2;

FIG. 4 is a vertical sectional view taken on the plane of the line 44 of FIG. 3;

FIG. 5 is a perspective view of the Scotch yoke drive for the compressor pistons as viewed from the plane of the line 5-5 of FIG. 3; and

FIG. 6 is a sectional view of the same as taken on the line 6-6 of FIG. 5.

The essential concept of this invention involves a geartype oil pump mounted externally on the side wall of the oil-reservoir portion of a compressor housing in which housing is formed a conduit leading to the drive shaft and communicating therethrough with an arrangement of interconnecting channels extending to all relatively moving surfaces of the compressor assembly, the oil pump having direct communication internally of the compressor with both the reservoir portion thereof and the said conduit, whereby the pump unit, as an individual component, may be readily removed and replaced without dismantling the compressor structure.

A compressor lubricating system embodying the foregoing concept comprises a compressor housing 5, a main drive shaft 6, opposed reciprocating pistons 7 and 8, and an oil pump 9 operated to feed lubricating oil to a system 10 of intercommunicating channels formed in the several moving parts of the compressor assembly. The several figures show these parts in a more or less diagrammatic form and relationship to indicate a conventional compressor and illustrate one manner of embodying this improved lubricating system in a machine involving a series of relatively-moving parts requiring constant lubrication. Therefore no attempt is made to show and describe a complete compressor unit, only the elements requiring pressure lubrication being referred to.

The housing 5 here shown is of hollow generally rectangular form mounting the drive shaft 6 on bearings 11 pump 9.

in the upper portion of the housing whereby the lower portion thereof constitutes an oil reservoir 12. One side wall 5.1 of the housing 5 is formed with an opening 13 (FIG. 3) for the reception of the pump 9 and from one side of this opening 13 and oil conduit 14 leads upwardly to an annular pocket 15, embracing the shaft 6, to feed oil to the channel system 10, as presently will be explained more fully.

.As shown the conduit 14 is formed within a boss or rib 14.1 integrally on the inner surface of the wall 5.1, which boss or rib extends from the opening 13 to an annular portion 14.2 through which the shaft 6 passes, the pocket 15 in the portion 14.2 opening to and surrounding the shaft periphery. At the lower end of the boss or rib 14.1 the conduit 14 opens to an inlet 14.3 which is located to meet and communicate with the discharge outlet 24 of the It will be understood, however, that the conduit 14 and pocket 15 may be contained within a separable member, suitably secured to the wall 5.1, or formed as an open channel in the inner wall surface which is merely enclosed by a suitable cover plate. In any event the conduit 14 and pocket 15 are a part of the wall structure, however they may be enclosed, and are fixed and permanent internal elements of the compressor assembly providing constant communication between the pump outlet 24 and the drive shaft 6.

The shaft 6, medially of the bearings 11, mounts an eccentric crank or drive member 16 journaled in a slide block 17 slidingly supported in a rectangular flame 18 and constituting a more or less conventional Scotch-yoke drive 19for the reciprocating pistons 7 and 8.

The pistons 7 and '8, of conventionally different diameters, are opposedly supported in cylinders 21 and 22 at diametrically opposite sides of the shaft 6 and are connected rigidly to opposite sides of the yoke frame 18 in a conventional manner by brackets 7.1 and 8.1 integral on the yoke 18.

The pump 9 here is shown as a conventional gear type. It is so mounted in the housing opening 13 that its inlet 23 (FIG. 4) is in direct communication with the oil in the reservoir 12 and its outlet 24 registers with the inlet end 14.3 of the housing conduit 14. Preferably the body of the pump 9 is peripherally flanged, as at 25, and is secured to the outside of the housing wall 5.1 by suitable removable fasteners 25.1 which pass through the flange. Thus the body of the pump, inwardly of the flange may be received in the opening 13 and the mounting sealed by means of a suitable gasket disposed beneath the flange. With such a mounting the pump may be readily removed for inspection, repair, or replacement at any time and the compressor, itself, need not be disturbed.

The system of channels 10 initiates with a primary axially extending channel 26 in the shaft 6, oppositely terminating at intersecting radial branches 27 in the area of the bearings 11 and having an intermediate intersecting radial branch 28 in the plane of the eccentric or crank 16. The branch 28 extends diametrically through the eccentric 16 and opens into an annular channel 29 formed in the surface of the bore of the slide block 17 in which the eccentric or crank 16 is journaled. The annular channel 29 has oppositely extending branches 30 which lead to the sides of the slide block which engage the inner walls of the yoke 18 and, as shown in FIGS. 5 and 6, the side surfaces of the slide block 17 are provided with elongate, vertically extending slots or pockets 31 into which the branches 30 open. These pockets or slots 31 are located medially of the slide block 17, between its top and bottom ends, and extend a sufiicient vertical distance so as to be in continuous open communication with passages 32 which extend axially of the pistons 7 and 8 from the inner wall of the yoke 18, through the connecting arms or brackets 7.1 and 7.2 to the in- 4:3 terior of the pistons. Inside the pistons, and extending diametrically through the hub portion thereof which is not shown, are lateral branch passages 33 which open to the. periphery of the pistons and the respective cylinder walls.

From the foregoing it will now be seen that the several oil passages are at all times in communication with the main supply passage 26 extending axially in the shaft 6, and that the various passages lead to every surface which engages and moves relative to another surface, so that all friction areas are under a continuous supply of lubricant from the main shaft passage 26.

The initiating shaft channel 26 is supplied by an intersecting radial branch 3'6v located in the plane of the annular pocket 15 in the enlarged portion 14.2 of the conduit boss 14.1. This branch 36 is thus in constant communication with the oil supply conduit 14 leading from the pump 9.

The shaft 6 is driven from a suitable source of power (not here shown) to operate the compressor and is connected by gears 37 and 38 to drive the pump 9. Thus the speed of the pump will always be proportional to the speed of the compressor and the quantity and pressure of the lubricant supplied to the compressor will be in direct relation to the friction load.

In the operation of my improved compressor lubricating system the shaft 6, through the gears 37 and 38, drives the pump 9 in the direction of the arrow 39 (FIG. 1) and causes oil to be drawn from the reservoir 12 through the pump inlet 23 (FIG. 4) and be pressured in the direction of the arrow 40 up through the housing conduit 14, to the pocket 15, through the passage 36 and into the axial channel 26 in the shaft 6. Flowing to opposite ends of the channel 26, under constant pressure, oi] emerges from the radial branches 27 to lubricate the bearings 11, and from the medial radial branch 28 in the crank 16 to the slide block 17 and the pockets 31 in the outer side surfaces thereof.

The pockets 31 are of such length as to be somewhat longer than the stroke of the slide block, as it moves up and down in the yoke 18 under the influence of the eccentric or crank 16 on the shaft 6, and since these pockets are centered on the axes of the pistons when the slide block is in a medial position the passages 32 leading into the pistons will be continuously supplied with lubricant for lubricating the cylinder walls.

The speed of the pump 9 will, of course, be determined by the compressor speed and the ratio of the gears 37 and 38. Preferably the pump will be operated at a lesser speed than the compressor, particularly when the compressor is a component in an automotive air conditioning system and is driven by a power take-ofl? from the vehicle motor. However in any case the pressure of the lubricant will be directly proportional to the lubrication requirements of the system. Also the pump, being an externally mounted component of the compressor unit can be readily removed and replaced whenever required and dismantling or disconnecting the compressor from the system in which it is incorporated is unnecessary in case of pump failure.

Although but one specific embodiment of this invention is herein shown and described it will be understood that numerous details of the construction shown may be altered or omitted without departing from the spirit of the invention as defined by the following claim.

I claim:

In a compressor comprising, a housing having an oil reservoir therein, a rotatable drive shaft extending into the housing through one wall thereof, bearing to journal the said shaft, a pair of opposed pistons and cylintiers therefor within said housing, and eccentric means of circular configuration on said shaft operatively connected by a Scotch yoke to reciprocate the pistons in said cylinders; said Scotch yoke comprising a rectangular yoke element having parallel side members, each directly and rigidly connected to a respective one of said pistons, and a rectangular slide block mounted between said side members in sliding engagement therewith, said slide block having an annular central opening receiving and slidably fit ting the periphery of said eccentric; a lubricating system comprising an axially extending passage in said drive shaft having a radial branch passage leading to the periphery of said eccentric, a continuous peripheral channel in the wall of said slide block opening in the plane of said branch passage, a pocket in each of the outer walls of said slide block which engage the side members of said yoke element, passages connecting said peripheral channel with each of said pockets, an axial passage in each of said pistons leading to the inner surface of the respective side member of said yoke element, said pistons each having radial passages leading from its axial passage to the outer piston wall, and means for supplying oil under pressure from said reservoir to the axial passage of said drive shaft adjacent one end of the shaft, each of said slide block pockets extending in the direction of slide block movement relative to said yoke element and being of such length and so disposed as to be in constant communication with the respective axial passage of said pistons.

References Cited in the file of this patent UNITED STATES PATENTS 1,616,913 McCallum Feb. 8, 1927 1,961,451 Phillips et al. June 5, 1934 2,025,187 Werner et al. Dec. 24, 1935 2,071,913 Bentley Feb. 23, 1937 2,257,707 Sladky Sept. 30, 1941 2,504,528 Hume Apr. 18, 1950 2,751,145 Olcott June 19, 1956 

